<template>
    <!-- 布局组件 -->
    <el-container class="home-container">
        <!-- 头部区 -->
        <el-header>
            <div>
                <img src="../assets/heima.png" alt="">
                <span>电商后台管理系统</span>
            </div>
            <el-button type="info" @click="logout">退出</el-button>
        </el-header>
        <!-- 页面主体区 -->
        <el-container>
            <!-- 侧边栏 -->
            <el-aside :width="isCollapse?'64px':'200px'">
                <div class="toggle-button" @click="toggleCollapse">|||</div>
                <!-- 侧边栏菜单区域 -->
                <!--
                unique-opened:每次只能展开一个菜单
                collapse:是否折叠
                collapse-transition：折叠动画
                router:是否使用 vue-router 的模式，启用该模式会在激活导航时以 index 作为 path 进行路由跳转
                default-active: 当前激活菜单的 index
                -->
                <el-menu
                        background-color="#333744"
                        text-color="#fff"
                        active-text-color="#409eff"
                        unique-opened :collapse="isCollapse"
                        :collapse-transition="false"
                        router
                        :default-active="activePath">
                    <!-- 一级菜单 -->
                    <el-submenu :index="item.id+''" v-for="item in menulist" :key="item.id">
                        <!-- 一级菜单的模板 -->
                        <template slot="title">
                            <!-- 图标 -->
                            <i :class="iconsObj[item.id]"></i>
                            <!-- 文本 -->
                            <span>{{item.authName}}</span>
                        </template>
                        <!-- 二级菜单 -->
                        <el-menu-item :index="'/'+subitem.path" v-for="subitem in item.children" :key="subitem.id"
                                      @click="saveNavState('/'+subitem.path)">
                            <!-- 二级菜单的模板 -->
                            <template slot="title">
                                <!-- 图标 -->
                                <i class="el-icon-menu"></i>
                                <!-- 文本 -->
                                <span>{{subitem.authName}}</span>
                            </template>
                        </el-menu-item>

                    </el-submenu>

                </el-menu>
            </el-aside>
            <!-- 右侧内容主题区 -->
            <el-main>
                <!-- 路由占位符 -->
                <router-view>
                </router-view>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
    export default {
        name: "Home",
        // 声明周期函数，一加载该页面，就发起请求
        created() {
            this.getMenuList()
            this.activePath = window.sessionStorage.getItem('activePath')
        },
        data() {
            return {
                // 左侧菜单数据
                menulist: [],
                iconsObj: {
                    '125': 'iconfont icon-user',
                    '103': 'iconfont icon-tijikongjian',
                    '101': 'iconfont icon-shangpin',
                    '102': 'iconfont icon-danju',
                    '145': 'iconfont icon-baobiao'
                },
                // 不折叠
                isCollapse: false,
                // 被激活的链接地址
                activePath:''
            }
        },
        methods: {
            logout() {
                window.sessionStorage.clear()
                this.$router.push("/login")
            },
            // 获取所有的菜单
            async getMenuList() {
                const {data: res} = await this.$http.get('menus')
                if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
                this.menulist = res.data

            },
            // 点击按钮，切换菜单的折叠和展开
            toggleCollapse() {
                this.isCollapse = !this.isCollapse
            },
            // 保存链接的激活状态
            saveNavState(activePath){
                window.sessionStorage.setItem('activePath',activePath)
                this.activePath = activePath
            }
        }
    }
</script>

<style scoped>
    .home-container {
        height: 100%;
    }

    .el-header {
        /* 背景色 */
        background-color: #373d41;
        /* flex 用法 https://www.cnblogs.com/hellocd/p/10443237.html */
        display: flex;
        justify-content: space-between;
        /* 控制图片的左边距 */
        padding-left: 0;
        /* 退出不贴边 */
        align-items: center;
        /* 字体颜色和大小 */
        color: #fff;
        font-size: 20px;
    }

    .el-header div {
        /* flex 用法 https://www.cnblogs.com/hellocd/p/10443237.html */
        display: flex;
        align-items: center;
    }

    .el-header span {
        margin-left: 15px;
    }

    .el-aside {
        background-color: #333744;
    }

    /* 解决侧边栏没对齐问题 */
    .el-aside .el-menu {
        border-right: none;
    }

    .el-main {
        background-color: #eaedf1;
    }

    .iconfont {
        margin-right: 10px;
    }

    .toggle-button {
        background-color: #4a5064;
        font-size: 10px;
        line-height: 24px;
        color: #fff;
        text-align: center;
        letter-spacing: 0.2em;
        cursor: pointer;
    }

</style>
